COVID-19: Presymptomatic or Asymptomatic?

Asymptomatic or presymptomatic for COVID-19?

By Megan Brooks

April 13, 2020 -- Asymptomatic or presymptomatic for COVID-19? Experts with the Infectious Diseases Society of America (IDSA) discussed the shift in thinking between the two terms at a media briefing Friday.

They also addressed racial disparities surrounding COVID-19, and announced new IDSA guidelines for diagnosis and treatment of the illness.

Regarding the shifting thinking on symptoms and transmission of the novel coronavirus, when it comes to presymptomatic or asymptomatic, "pre" is really the right terminology, Carlos del Rio, MD, professor of medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, Georgia, said during the briefing, because it's not that people are asymptomatic but that they develop symptoms later and start transmitting the virus 24 to 48 hours before they develop symptoms.

"Clearly, this plays a role in transmission," with some studies suggesting that 6% to 12% of transmissions occur during this presymptomatic stage, he explained.

Jeanne Marrazzo, MD, MPH, director of the Division of Infectious Diseases at University of Alabama at Birmingham, noted that early in the COVID-19 pandemic, the presymptomatic phase "could have been missed because we didn't realize the wide ranging symptoms this disease has."

This is turning out to be a "very interesting" virus with "fascinating" symptoms, she told reporters on the call.

The virus seems to have capacity to affect far more than just the respiratory tract. Initially, however, it was viewed "very much like a classic respiratory viral infection. As a result, a lot of people were refused testing because they were not showing the classic signs" of respiratory infection, Marrazzo noted.

It's now clear that the range of symptoms is quite different, she said.

Notably, loss of smell seems to be "very characteristic and very specific to this infection. I can't think of another common viral infection that causes loss of smell before you start to see other things," Marrazzo said.

Data also suggest that gastrointestinal symptoms are common with COVID-19. Early data suggest that diarrhea probably occurs in about one third of patients. Some people have reported abdominal pain as the first sign, she said.

"Now that we know about the more wide range of symptoms associated [with COVID-19], we are being much more open to considering people perhaps having this infection. There is a lower index of suspicion and much lower threshold for diagnostic testing," Marrazzo said, adding that there are still many barriers to testing and getting test results.

Stark Racial Disparities Need Greater Understanding

The second major topic of discussion at the briefing was the growing realization of racial disparities in COVID-19.

"Racial disparities in our country are not new but racial disparities in this disease are pretty stark," del Rio said. "We live in a country where disparities have really colored a lot of what our diseases are, from HIV to diabetes to hypertension, and it's not surprising that we are seeing this now with COVID-19."

Marrazzo noted that, in Alabama, around 20% of the population is African American, yet almost 40% of COVID-19 deaths are occurring in this population. "The most stark statistics are coming out of Illinois and Michigan, where less than around 15% of the population is African American and yet 70% of the deaths are occurring in that group," she said.

Both del Rio and Marrazzo agreed that understanding the racial differences in COVID-19 deaths is going to require a lot of analysis in the coming months.

Part of it likely reflects the challenge of social distancing in urban areas, Marrazzo said. "Social distancing is a luxury afforded by having a really big space, and space is money."

The other long-standing challenge of unequal access to healthcare also likely plays a role, she said. This includes missing out on preventive health appointments and screenings, which can translate into more comorbidities, particularly hypertension.

The evolving evidence about the virus, and the stark conditions that frontline clinicians face, make this an especially challenging public health crisis, del Rio said.

"Taking care of these patients is incredibly taxing and my hat is off to physicians, residents, nurses, everybody working on this in the hospitals because they are really doing a yeoman's work," he said.

"These are not easy patients to take care of. Not only are [the frontline clinicians] providing care, they are caring for the patient and providing a comfort and someone to listen to when family can't be present," del Rio emphasized.

New Guidelines

The IDSA just released new guidelines for diagnosis and treatment of COVID-19.

"We are learning new things every day about this virus. Things are rapidly changing, and as we learn new things we have to adapt and make changes," del Rio said.

del Rio noted that the guildelines "will evolve and change as more information comes out."

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References
SOURCE: Medscape, April 13, 2020.
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